Slip clutch



E. F. HUDDLE oci. 2o, 1931.

SLIPv CLUTCH Filed Jan. 19. 1928 Patented Oct. 20, 1931 I UNITED STATESy PATENT OFFICE EDWIN FREDERICK HUDDLE, oFiMoLINE', ILLINOIS, AssIeNoR'ro DEERE a COMPANY, u

or MOLINE, ILLINOIS, a CORPORATION or ILIJNoIs` l SL11 CLUTCH: j

Application led January 19, 1928. Serial No. 247,972. i

The present invention relates to slip clutches such as are commonlyemployed in power transmitting connections, `where .they serve asoverload relief devicesto prevent breakage of the driving or drivenparts in sibility of the operator of the implement be,

ing injured by the working parts of the clutch, nor of his clothing orany other ex- 2o traneous material becoming caught in the clutch. YAnother lobject the spring pressure efective upon the clutch surfacescan be easily and quickly adjusted Without the necessity of obtainingaccess to the interior of the clutch housing.

Another object of the invention is to provide a construction in whichthe active clutch surfaces can be easily and cheaply renewed in theevent of wear or breakage, thereby avoiding the necessity of discardingthe clutch, or substituting relatively expensive parts thereof.

Other objects and advantages of the invention will appear in thefollowing description of a preferred embodiment thereof. In theaccompanying drawings illustrating such embodiment:

Fig. 1 is a longitudinal sectional view through the clutch.

Fig. 2 is a longitudinal sectional view through the clutch housing withthe operating parts of the clutch illustrated in elevation.

Fig. 3 is an end view of the clutch, corresponding to a section taken onthe plane of the line 3-3 of Fig. 1.

Fig. 4 is a sectional view of the inner end of the housing, takenapproximately on the of the invention is to pros vide a construction yofslip clutch In which .onal cross section for establishing a secure planeof the line 4--4 of Fig. 1, advvith the A associated clutch discremoved.` y

Fig. 5 is an elevational view of the rear side of one of the clutchdiscs, and

Fig. 6 is a view of the toothed side ofthe clutch disc,

l The clutch is illustrated as being interposed in a line of shaftingrepresented by the two shafts .8 and9. Either shaft may be regarded asthe driving element, but for the purposes of the present descriptionlthe shaft 8 will be considered as the driving element and the shaft 9as the driven element. It will n be notedthat the portion of the drivingshaft 8 which is enclosed in the clutch housing is of square vorpolygonal cross section, as indicated at 11. A short bearing extension12 projects from the end of the driving shaft 8*"to have bearingenga-gement with the clutch housing and thereby afford a two-pointbearing support between the shafts or between the drivingshaft and theclutch housing, as will presently appear. The.,y adjacent endof thedriven shaft 9 is also of square or polygdriven connection with theClutch parts.

Mounted on the two shafts and completely f enclosing the active clutchparts is a ho11s ing 13 comprising two longitudinally adjustablesections 14 and'15. The section 14 comprises a relatively long, tubularboss or hub 16 at one end thereof, which has a bore 17 of square orpolygonal cross section to engage non-rotatably over the driven shaft 9.A pin 18 is preferably extended through the hub 16 and shaft 9 torigidly se'cure the same together. Formed at the inner end of the bore17 is a bearing surface 19 of reduced diameter, in which the 'bearingextension 12 has snug bearing engagement. A lubricatl ing passage 21extends down through the hub 16 for supplying lubricant to the bearingsurface 19. The hub 16 is joined to the large outer portion of thehousing' section 14 through a radially extending end wall or flange 22,to the inner side of which the driven clutch disc has coupledconnection, as will be presently described. Any suitable arrangement ofreinforcing ribs 23 is ex- 100 r tating the housin tended between theend wall 22 and the hub 16.

The other housing section 15 comprises an end hub or boss 24 which hasrotative bearin engagement on the cylindrical portion o the drive shaft8. The housin section 15 extends within the housing section 14, and theengaging surfaces ofthe two sections are threaded as indicated at 25 toprovide for longitudinal ad'ustment between the sections. It will beevldent that b rosection 15 relative y to the section 14, the ength ofthe housing can be increased or diminished. In order to hold the twosections in any extended or contracted adjustment, a set screw 26 isthreaded inwardly through a boss in the outer housing se'ction 14 toengage the inner housinlg section 15. A plurahty of longitudinal yextending grooves ordepressions 27 are formed at spaced points aroundthe periphery of the housing section 15, in whichrgrooves the set screw26 is adapted to be seated so that it will not damage the threads 25.Slidably mounted on the driving shaft 8 within the housing 14-15 is asleeve 29 of square cross section for engaging non-rotatably on thesquare portion 11 of the shaft. The shifting movement of the sleeve 29is preferably limited by a pin 31 which passes through the shaft and hasits projecting ends disposed in diametrically opposite, longitudinallyextending slots 32 formed in the sleeve. Projecting radially from theinner end of the sleeve is a iiange or head 33 which carries the drivingclutch disc. A heavy compresision spring 34 surrounds the sleeve 29 andis confined between the flange or head 33 and the end wall of thehousing section 15.

The drive is transmitted from the sleeve 29 to the housing section 14through .the interengagement of two cooperating vclutch discs 35 and 36which are carried by each of said elements. Said clutch discs aresubstantial duplicates so that one disc may be interchanged for theother.

Each disc has its clutch face formed with .teeth or serrations 37 whichextend radially of the face of the disc, as shown in Fig. 6. Such teethor serrations are formed as symmetrical projections and indentationshaving rounded end surfaces and relatively obtuse side surfa'ces, asshown in Fig. 2. The toothed surfaces, or the entire surfaces of thedises, are preferably case hardened to withstand wear due to friction.The teeth on the opposing clutch faces are adapted to mesh or match witheach other, and when so engaged under the pressure of the spring 34 theyare capable of transmitting a relatively heavy driving torque. However,when overload slippage does occur, these surfaces will ride over eachother without destructive wear or vibration. The rear face of each discis formed with a plurality of radially extending driving keys or lugs 38which are preferably spaced equidistantly about the face of the disc, asshown in Fig. 5. These keys or lugs are also preferably ltapered onsubstantially radial lines toward the axial opening 39 in the disc. Suchkeys or lugs establish driving engagement between the driving disc 35and the flange 33, and between the driven dis'c 36 and the end wall orflange 22 of the housing section 14. In the case of the driving d1sc 35the keys 38 engage in radiall extending recesses or grooves 41 forme inthe face of the flange 33. In the case ofthe driven disc 36 these keysalso between the clutch discs .and the driving and driven parts of theclutch, while still per mitting convenient removal of the clutch discswhen it is desired to repair the same or to replace the discs.

In the operation of the clutch, the housing 14--15 rotates continuouslywith the driving shaft 8. When an excessive load is placed upon saidshaft, the coacting teeth 37 on the two clutch discs exert a cammingaction on each other in opposition to the pressure of the spring 34,whereby the sleeve 29 is caused to shift rearwardly to a degreesufficient to4 permit the teethv of the driving clutch disc 35 to slideover the teeth of the driven clutch disc 36. As shown in Fig. 1, the endwall of the housing section 15 may 'be provided with an annular recess42 to provide ample clearance for this shifting movement of the sleeve29. It will be observed that a two-,point bearing support is maintainedbetween the shaft 8 and the housing 14-15, at the bearing surfaces 19and 24, irrespective of whether the clutch is transmitting drivingrotation or is slipping under an overload torque., During the lattercondition of operation, the shaft 8 is rotating within the bearing boss24 of the housing, the latter remaining stationary with the shaft 9.AWhen it is desired to adjust the clutch for `slippage at either a higheror lower torque, it is only necessary to release the set screw 26 and tothen screw the housing section 15 inwardly or outwardly with referenceto the housing section 14, thereby varying the pressure of the spring34. In the event that one or both of the active clutch surfaces shouldbecome worn or broken, the same can be easily and quickly renewed bymerely opening the housing and substituting the damaged clutch disc ordiscs. Hence, wear between the active clutch surfaces does notnecessitate replacing the entire clutch, or renewing relativelyexpensive parts of its construction. The engagement of the pin 31 in theslots 32 serves t'o prevent displaceshaft 8, so that when the housingsections 14 and 15 are-screwed apart' and the two shafts are moved `outof alinement,preparatory to renewing the clutch discs or inspecting theclutch, the sleeve 29 will be held against slipping off the end of theshaft 8. v

l. In a slip clutch, the combination of driving and driven members, twoclutch discs having coa'ctingY clutch teeth ontheir front faces adaptedto transmit` rotation between said discs, and radially disposedshoulders on the rear faces of said discs adapted to engage releasablywith radiallydisposed shoulders on said members for transmittingrotationbetween said members and said discs.

2. In a slip clutch, the combination of axially alined driving anddriven shafts, flange members extending substantially radially from eachof said shafts, one of said flange members being slidable along itsshaft, coacting clutch' discs disposed between said flange members, theopposing faces of said discs having slip clutch teeth thereon, andradially disposed driving keys on the rear faces of said discs engagingwith radial driving shoulders on said flange members.

In a slip clutch, the combination of axially alined driving and drivenshafts, flange members extending substantially radially from each ofsaid shafts, one of said flange members being slidable along its shaft,a spring bearing against said latter flange member tending to move saidflange members together, coacting clutch discs disposed between saidflange members, said clutch discs being substantial duplicates and bothhaving matching clutch teeth on their opposing surfaces, and radiallyextending driving keys projecting from the opposite surfaces of saiddiscs and engaging in radial recesses in said flange members.

4. In a slip clutch, the combination of axially alined driving anddriven shafts, a sleeve slidable on one of said shafts, a clutch discremovably mounted on and having clutching engagementwith saidsleeve,acoacting clutch disc having non-rotative association with theother of said shafts, said latter clutch disc being removably mounted,slip clutch teeth formed in the opposing faces of said clutch discs, aspring coacting with said sleeve for forcing said clutch discs together,and a housing enclosing said clutch discs and said spring, and havingbearings for one of said shafts at opposite sides of said sleeve andclutch discs. l

5. In a slip clutch, the combination of axially alined driving anddriven shafts, a sleeve slidably mounted on the end of'one of saidshafts, a housing rotating with one of said shafts and extending oversaid sleeve, said housing providing a two-point bearing support for theother of said shafts, a spring operating to slide said sleeve along theshaft on which itis mounted, a Aclutch disc having radial shoulders enga'ng with radial shoulders on said sleeve,an a coacting clutch dischaving radial shoulders engaging with radial shoulders yin the end ofsaid housing.

6. In a slip clutch of the class described, the combination of axiallyalined driving and drivenshafts, a sleeve slidablyfmounted on thedriving shaft, a housing extending over said sleeve and'havingnon-rotative connection with the driven shaft, a spring confined betweenVone end of said housing and said sleeve for normally tending to movesaid sleeve toward the other end of said housing, a clutch discremovably mounted `on said sleeve, and a coacting clutch discnon-rotatably engaging in the lend of said housing, said housingcomprising -two housing sections adjustable relatively to each other foradjusting the pressure of said spring, and each having a bearing for thedriving shaft.

7. In a slip clutch,the combination of axially alined driving and drivenshafts, a first housing section non-rotatably secured to the drivenshaft, a'second housing section having adjustable threaded engagementwith said first housing section, said second housing section comprisinga bearing surface rotatably engaging the driving shaft, a sleeveslidably r' mounted on said latter shaft within said housing sections, aflange at ,one end of said sleeve, a compression spring confined betweensaid flange and the end of said second housing section, and a pair of'coacting clutch discs confined between said flange andthe end wall ofthe first housing section, the opposing-faces of said 'clutch discshaving clutch teeth thereon, `and 'the opposite'lsurfaces of said discshaving radially disposed driving keys projecting therefrom for engagingin radially disposed recesses iny said flange and in the end wall ofsaid first housing section. 8.` In a slip clutch of the class described,the combination of axially alined driving and driven shafts, a clutchhousing comprising first andl second housingsections, said first housingsection being rigidly secured to said driven shaft, said second housingsection having rotative bearing support on said driving shaft, one ofsaid housing sections screwing into the other to permit said housing tobe lengthened or shortened, `a sleeve mounted on said driving shaftwithinsaid housing, a pin projecting from the latter shaft and engagingin a longitudinal slot in said sleeve for limiting sliding movementofsaid sleeve, a flange on one end of said sleeve, a compression springconfined between said flange and the end wall of said second housingsection, a pair of removable clutchdiscs confined between said flangeand the end wall of said first housing section, sloping clutch teeth onthe opposing facesof said discs, and radially extending driving-keys onthe opposite faces of said discs adapted to engage in radially disposedrecesses in said fiange and in the end wall of said first housingsection.

9. In a slip clutch of the class described the combinatlon of axiallyalined driving and driven shafts, a clutch housing comprising first andsecond housing sections, said housing adapted to turn with said drivenshaft, bearin in said housing providing a two point Journaling supportto hold said driving shaft against lateral stresses, flange membersextendin substantially radially from each of said s afts, one of saidfiange members being slidable along its shaft, coacting clutch disksdisposed between said ange members, said clutch discs havingcorrugations on their inner faces and radial ribs on their outer facesand bein' interchangeable on said shafts and in said housing.

10. In a clutch of the class described, the combination of axiallyalined driving and driven shafts, a clutch housing comprising first andsecond housing sections, one of said housing sections screwing into theother to permit said housing to be lengthened or shortcned, flangemembers extending substantially radially from each of said shafts, oneof said flange members comprising a sleeve, a compression sprin on saidsleeve and confined between said flrst housing section and said flange,said sleeve being slidable longitudinally along the driving shaftagainst the tension of said spring, a pin through said driving shaft andsaid sleeve to limit the movement of the latter on said shaft, said pinacting to hold the spring and sleeve on said drivmg shaft when theclutch is dismantled, interchangeable clutch discs disposed between saidiange members, said clutch discs cooperating with said flange membersagainst radial movement between the shafts, and matched serrations onthe inner faces of said clutch discs for transmitting normal drivetherethrough.

l1. In a slip clutch of the class described, the combinatlon of axiallyalined driving and driven shafts, a sleeve slidably mounted on thedriving shaft, a housing extending over said sleeve, a spring confinedbetween one end of said houslng and said sleeve for normally tending tomove said sleeve toward the other end of said housing, removable.

clutch discs disposed interchangeably between said sleeve and `theopposite end of said housing, said discs having coacting serrations ontheir inner sides and radial keys on their outer sides, said serrationsholding said discs against relative rotation under normal drivingstresses, and said keys holding the discs in non-rotatable relationshipwith the sleeve and housing, respectively, said housing comprising twohousing sections adjustable relatively to each other for adjusting'thepressure of said spring, and each having a bearing for the drivingshaft.

12. In a slip clutch of the class described,`

the combinatlon' of axially alined driving and driven shafts, a sleeveslidably mounted on the driving shaft, a housing extending over saiadsleeve, and having non-rotative connection with the driven shaft, aspring confined between one end of said housing and said sleeve fornormally tending to move said sleeve toward the other end of saidhousing, a clutch disc removably mounted on said sleeve, and a coactinclutch disc non-rotatably engaging in t e end of said housmg.

13. In a clutch of the class described, the combination of axiallyalined driving and driven shafts, a sleeve slidably mounted on thedriving shaft, a housing extending over said sleeve, a spring confinedbetween one end of said housing and said sleeve for normally tending tomove said sleeve toward the other end of said. housing, a plurality ofremovable clutch discs disposed between said .sleeve and the oppositeend of said housmg, sald discs being substantially identical and eachhaving coactin serrations on their inner sides and radial eys on theirouter sides, said keys holding the discs in non-ro` tatable relationshipwith the sleeve and housing, respectively.

In witness whereof, I hereunto subscribe my name this 9th day ofJanuary, 1928.

EDWIN FREDERICK HUDDLE.

